Bug#208308: libc6: Still happens, and doesn't actually conform to the manual pages

[Mike Hommey <mh+reportbug@glandium.org>]

Package: libc6
Version: 2.7-9
Followup-For: Bug #208308

Bug #208308 is the reason for bug #456653. And it shouldn't happen.

With the following testcase, it happens while it shouldn't, according to
the manual:
-----8<-------
#include <stdio.h>
#include <locale.h>

#define STR "²éľÂíɱ²¡¶¾£¬ÖܺèµtÄúµÄ360²»×¨Òµ£¡"

int main(void) {
	char buf[200];
	setlocale(LC_ALL, "");
	printf("%d\n", snprintf(buf, 150, "%.50s", STR));
	return 0;
}
----->8-------

The manual page has this to say:
 About precision:
  An optional precision, in the form of a period (‘.’)  followed by an
  optional decimal digit string.(...) This gives (...) the maximum
  number of characters to be printed from a string for s and S
  conversions.

 About s:
  If no l modifier is present: The const char * argument is expected to
  be a pointer to an array of character type(...)

  If an l modifier is present: The const wchar_t * argument is expected
  to be a pointer to an array of wide characters.  Wide characters from
  the  array  are converted  to  multibyte  characters (...)

There is no "l" modifier, but still, the string goes through the
multibyte conversion code, and fails because the string is invalid
multibyte.

Mike

-- System Information:
Debian Release: lenny/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.24-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages libc6 depends on:
ii  libgcc1                    1:4.3.0~rc2-1 GCC support library

libc6 recommends no packages.

-- debconf information:
  glibc/upgrade: true
  glibc/restart-failed:
  glibc/restart-services: